Cryptography

Module description

Aims and Learning Outcomes

To introduce both theoretical and practical aspects of cryptography, authentication and information security.

On successful completion of this module, students will be able to:

• Understand the relevant mathematical techniques associated with cryptography
• Understand the principles of cryptographic techniques and perform implementations of selected algorithms in this area
• Systematically apply security techniques in solving real-life security problems in practical systems

Syllabus

An indication of the types of topics:

Basic terminology and concepts:

• Goals of cryptography, terminology and notation, players, basic cryptographic functions

Number theory preliminaries:

• Congruent modulo n, equivalent class modulo n, Integer modulo n (Zn)
• Multiplicative inverse
• Relative prime
• Fermat's little theorem
• Euler's theorem
• EEA (Extended Euclidean Algorithm)
• CRT (Chinese Remainder Theorem)

Ciphers:

• Block ciphers (substitution, transposition, product)
• Stream ciphers
• Modes of operation (ECB, CBC, CFB, OFB)

Cryptosystems:

• Block cipher: DES (Data Encryption Standard), AES (Advanced Encryption Standard)
• Public-key: RSA (Rivest-Shamir-Adelman), El Gamal
• One-way hash function: SHA and MD5 (Message Digest 5)

Key-establishment protocols:

• Symmetric and asymmetric techniques (Diffie-Hellman, Needham-Schroeder, Otway-Rees)
• Public-key encryption, basic and advanced Kerberos protocols

Authentication and identification:

• Concepts
• Fiat-Shamir and Feige-Fiat-Shamir protocols
• Zero-knowledge identification protocol
• Multi-factor Authentication, biometrics
• Password systems: number of acceptable passwords for a given password policy, exhaustive search, password ageing.

Digital signatures:

• Classification
• Digital signature schemes: RSA, EI-Gamal, DSA (Digital Signature Algorithm) and DSS (Digital Signature Standard)

Assessment details

Please note: The below assessment details for the 2024/25 academic year may be updated. The confirmed details will be available on the Student Handbook and on the module KEATS page at the beginning of the semester.

• 100% Examination

Semester 1 only study abroad students will be required to take this exam in an alternative assessment format in the January exam period.

Full year study abroad students will be required to take this exam in person in January.

Module description disclaimer

King’s College London reviews the modules offered on a regular basis to provide up-to-date, innovative and relevant programmes of study. Therefore, modules offered may change. We suggest you keep an eye on the course finder on our website for updates.

Please note that modules with a practical component will be capped due to educational requirements, which may mean that we cannot guarantee a place to all students who elect to study this module.

Please note that the module descriptions above are related to the current academic year and are subject to change.